Rosemary Oil for Hair Growth: A Scientific Deep Dive

Anytime I see people with long, healthy hair, I get jealous. I want it too, and it is not just about genetics; it is about your haircare routine. People with long, healthy hair don’t have it by chance; they have studied herbs, and if you know rosemary oil, it is one of the most talked-about herbs for hair growth, especially for afro-textured hair. Understanding the unique structure of Afro-textured strands is crucial when exploring how rosemary oil stimulates growth. If you’re new to the science of African hair, this article breaks down what makes it so different.

I have seen testimonies and praises of rosemary oil. It begs the question: Does rosemary oil really work for hair growth, or just another propaganda? As much as a lot of people say rosemary oil works for them, there are people for whom rosemary oil doesn’t work at all. This post will move past the hype to provide a scientific deep dive into the evidence behind using rosemary oil for hair growth.

As a pharmacologist, I analyse the chemical compounds, mechanisms, and clinical data behind health claims. I wanted to understand what makes rosemary oil stand out and whether its impact on hair growth is scientifically sound. In this post, we’ll explore the research, break down the mechanisms, compare rosemary oil directly to the FDA-approved treatment Minoxidil, and offer practical ways to use rosemary oil effectively for hair growth, especially if you’re dealing with thinning, shedding, or slow growth.

Let’s break down the evidence.

The Basics of Hair Growth

Before we get to how rosemary oil can stimulate hair growth, let’s take a look at how the hair grows in the first place. This will help us understand the best treatment for your hair. The three phases are:

Anagen (The Growth Phase)

This is the stage where the hair grows; it is known as the active phase of hair follicle growth. You need your hair to stay in this phase for consistent growth. Hair on your scalp can stay in this phase for anywhere from 2 to 7 years. The longer a hair remains in the anagen phase, the longer it will grow.

Catagen (The Transition Phase)

After the growth phase comes a short transitional stage that lasts for about 10 days. During this phase, the hair follicle shrinks and detaches from the blood supply. When there is shortage of blood supply, the hair enters the next stage.

Telogen (The Resting Phase)

This is the last stage and it is called the shedding phase. At this stage the hair follicles lies dormant for about three months. The old hair shaft rests in place, while a new hair begins to grow beneath it. At the end of this phase, the old hair is shed (what you see in your brush or shower drain), allowing the new hair to come through and begin its own anagen phase.

How growth treatment work

For any hair growth treatment to be effective, its primary goal is to influence this cycle. Specifically, successful treatments work by extending the anagen (growth) phase and/or shortening the telogen (resting) phase, resulting in more follicles actively growing hair for a longer period.

The Science and Benefits of Rosemary Oil For Hair Growth

Rosemary oil is an essential oil obtained from the rosemary plant native to the Mediterranean region. It has been used for centuries and is known for its aromatic fragrance. While dozens of compounds are present, a few key players are believed to be responsible for its hair growth properties.

The main chemical compounds of rosemary extract are αpinene, 1,8-cineole, camphor, rosmarinic acid, carnosic acid and borneol. These substances are found in both rosemary oil and rosemary leaf extract, although in different concentrations, and are known to have the following properties:

1. improves blood circulation

Just like any other organ, your hair follicles need a steady supply of oxygen and nutrients to thrive. Rosemary is known to improve blood flow to the scalp, possibly by stimulating the cells that line blood vessels and facilitating the movement of platelets. Rosemary oil can stimulate hair follicles and encourage faster hair growth by improving blood circulation in the scalp. Enhanced circulation ensures that the follicles receive the nourishment they need to stay firmly in the anagen (growth) phase.

2. Anti-inflammatory and Antioxidant

The oil has anti-inflammatory and antioxidant properties that soothe the scalp and reduce irritation. Oxidative stress, caused by an imbalance between free radicals and antioxidants, can lead to premature aging of the follicle. Carnosic acid is a powerful antioxidant that helps neutralize these damaging free radicals. By reducing inflammation and fighting oxidative stress, rosemary oil helps create a healthier, more stable environment on the scalp, which is more conducive to robust hair growth.

3. Nerve Healing and Follicle Stimulation

4. : Studies show that rosemary extracts can accelerate tissue regeneration and restore nerve endings around hair follicles. This effect is due to rosemary’s carnosic acid content, as this compound may have nerve-stimulating properties.

4. reduce the amount of dht in the scalp

Excessive Testosterone in men is transformed into DHT, which attaches to androgen receptors in hair follicles and leads to hair thinning. A hormone called dihydrotestosterone (DHT) is the common cause of hair loss, which contributes to male and female baldness. DHT then binds to receptors in hair follicles, causing them to shrink and eventually stop producing hair. A study revealed that Rosmarinus officinalis has a potent inhibitory activity on 5-alpha-reductase, reducing the amount of DHT on the scalp. This shows that rosemary extract can block DHT from binding to hair follicle receptors, providing a strong scientific basis for its use in pattern hair loss.

Rosemary Oil Vs Minoxidil For Hair Loss Treatment

Rosemary oil has always been compared with Minoxidil. Minoxidil is one of the most popular and best-studied treatments for hair loss. An impressive study compared rosemary oil with minoxidil. One group of men used rosemary oil. In the other corner, another group of men used 2% minoxidil. The results showed that:

• For the first 3 months, things were pretty quiet. Neither the rosemary oil group nor the minoxidil group saw any major changes. It was a classic case of “patience is a virtue.”

• But at the 6-month mark, the story changed dramatically. Both groups experienced a significant increase in hair count!

And here’s the punchline that had everyone talking: When scientists compared the final results, they found no statistical difference between the two groups. That’s right, the men who used rosemary oil saw the same amount of hair growth as the men who used 2% minoxidil.

My problem with the above study

• Abstract: This breakdown is based on the study’s abstract. An abstract is a summary, and while it gives us the key results, the full paper contains the nitty-gritty details. I always prefer to read the full text, so it’s good practice to view these exciting findings with that in mind.
• Strength Matters: The study used the 2% concentration of minoxidil. There is a stronger 5% version available, which was not tested in this particular comparison. The 5% is what dermatologists recommend for effectiveness.
• Duration: Yeah, 6 months does sound like a long time, but it’s not a long time for hair growth. Hair grows in a cycle, and it takes years. Remember the anagen phase we talked about previously.
• It’s One Study: While this was a fantastic and well-designed human trial, science loves repeated results. We’d love to see more studies confirm these findings.

This abstract serves as a starting point for discussion regarding rosemary oil and minoxidil. However, readers should exercise caution and seek out more extensive research before forming a definitive opinion on their comparative benefits.

How to Use Rosemary Oil Effectively To Grow Your Hair

Understanding the science is one thing, but applying it correctly is what makes the difference. If you’re considering trying rosemary oil, proper application and consistency are crucial for both safety and potential effectiveness. Here’s a practical guide to get you started. Before adding rosemary oil to your regimen, it helps to know your hair’s porosity. Here’s a simple porosity test for Afro hair to find out how well your strands absorb oils.

Rule #1: Dilution is Non-Negotiable

This is the most important rule. Essential oils are highly concentrated plant extracts. Applying pure, undiluted rosemary oil directly to your scalp can cause significant irritation, redness, burning, and even allergic contact dermatitis. To use it safely, you must dilute it in a carrier oil.

Recommended carrier oils

• Jojoba Oil: Its molecular structure is very similar to the natural sebum your scalp produces, making it lightweight and easily absorbed.
• Coconut Oil (Fractionated): A deeply moisturizing oil. Use fractionated coconut oil if you want it to remain in a liquid state for easy mixing.
• Castor Oil: Thicker and rich in ricinoleic acid, it’s a popular choice for hair treatments but may be too heavy for those with very fine hair.

Application Methods

You have two simple and effective options for incorporating diluted rosemary oil into your routine.

Apply directly to your scalp

This method allows for the most direct contact with your hair follicles. It’s the method most similar to that used in clinical studies.

• Recipe: Mix 3 to 5 drops of high-quality rosemary essential oil with one tablespoon of your chosen carrier oil.
• Application: Part your hair into sections and apply the oil mixture directly to your scalp, not just the hair strands. Using your fingertips, gently massage the oil into your scalp for 2-5 minutes. This not only ensures even distribution but the massage itself helps stimulate circulation. You can leave the treatment in for at least 30 minutes (or even overnight) before washing your hair as usual.
• After applying rosemary oil to your scalp, be sure to follow up with a good moisturizing routine. Here’s how to properly moisturize Afro hair so you don’t lose all that scalp-loving goodness.

Add it to your existing products

For a lower-maintenance approach, you can fortify your regular shampoo or conditioner.

• Add about 5 drops of rosemary oil for every ounce (approx. 30mL) of your shampoo or conditioner. Be sure to shake the bottle vigorously before each use to ensure the oil is well-dispersed. While this method is convenient, it provides less contact time than a dedicated scalp massage.

Frequency and Consistency: Manage Your Expectations

This is not an overnight fix. Clinical studies participants saw significant results at the 6-month mark, although most hair treatments take 2 years or above to see growth, so it’s important to be patient. The key to seeing any potential benefit is consistency. Aim to use your rosemary oil treatment two to three times per week. Choose a method that fits realistically into your schedule. Sporadic use once a month is unlikely to yield the results you’re hoping for. Just like a fitness routine, consistency over time is what builds results.

Final Thoughts

If you choose to incorporate rosemary oil into your routine, patience and consistency are paramount; results typically manifest over several months/years, not overnight. Before full application, it is crucial to perform a patch test on a small area of skin to rule out any potential allergic reactions or sensitivity. Rosemary oil may or may not work for you, but it is worth the try.

Want to pair rosemary oil with other nourishing products? Check out this list of the best hair products for African hair that work beautifully for natural growth.